1 /* SPDX-License-Identifier: GPL-2.0 */ <<
2 /* 1 /*
3 * Copyright (C) 2020-2022 Loongson Technology !! 2 * This file is subject to the terms and conditions of the GNU General Public
>> 3 * License. See the file "COPYING" in the main directory of this archive
>> 4 * for more details.
4 * 5 *
5 * Derived from MIPS: <<
6 * Copyright (C) 1994 - 2000, 2001, 2003 Ralf 6 * Copyright (C) 1994 - 2000, 2001, 2003 Ralf Baechle
7 * Copyright (C) 1999, 2000 Silicon Graphics, 7 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
8 * Copyright (C) 2001 MIPS Technologies, Inc. 8 * Copyright (C) 2001 MIPS Technologies, Inc.
9 */ 9 */
10 10
11 #include <asm/asm.h> 11 #include <asm/asm.h>
12 #include <asm/asmmacro.h> 12 #include <asm/asmmacro.h>
13 #include <asm/loongarch.h> !! 13 #include <asm/compiler.h>
>> 14 #include <asm/irqflags.h>
14 #include <asm/regdef.h> 15 #include <asm/regdef.h>
>> 16 #include <asm/mipsregs.h>
15 #include <asm/stackframe.h> 17 #include <asm/stackframe.h>
>> 18 #include <asm/isadep.h>
16 #include <asm/thread_info.h> 19 #include <asm/thread_info.h>
17 #include <asm/unwind_hints.h> !! 20
>> 21 #ifndef CONFIG_PREEMPTION
>> 22 #define resume_kernel restore_all
>> 23 #else
>> 24 #define __ret_from_irq ret_from_exception
>> 25 #endif
18 26
19 .text 27 .text
20 .cfi_sections .debug_frame <<
21 .align 5 28 .align 5
22 SYM_CODE_START(handle_syscall) !! 29 #ifndef CONFIG_PREEMPTION
23 UNWIND_HINT_UNDEFINED !! 30 FEXPORT(ret_from_exception)
24 csrrd t0, PERCPU_BASE_KS !! 31 local_irq_disable # preempt stop
25 la.pcrel t1, kernelsp !! 32 b __ret_from_irq
26 add.d t1, t1, t0 !! 33 #endif
27 move t2, sp !! 34 FEXPORT(ret_from_irq)
28 ld.d sp, t1, 0 !! 35 LONG_S s0, TI_REGS($28)
29 !! 36 FEXPORT(__ret_from_irq)
30 addi.d sp, sp, -PT_SIZE !! 37 /*
31 cfi_st t2, PT_R3 !! 38 * We can be coming here from a syscall done in the kernel space,
32 cfi_rel_offset sp, PT_R3 !! 39 * e.g. a failed kernel_execve().
33 st.d zero, sp, PT_R0 !! 40 */
34 csrrd t2, LOONGARCH_CSR_PRMD !! 41 resume_userspace_check:
35 st.d t2, sp, PT_PRMD !! 42 LONG_L t0, PT_STATUS(sp) # returning to kernel mode?
36 csrrd t2, LOONGARCH_CSR_CRMD !! 43 andi t0, t0, KU_USER
37 st.d t2, sp, PT_CRMD !! 44 beqz t0, resume_kernel
38 csrrd t2, LOONGARCH_CSR_EUEN !! 45
39 st.d t2, sp, PT_EUEN !! 46 resume_userspace:
40 csrrd t2, LOONGARCH_CSR_ECFG !! 47 local_irq_disable # make sure we dont miss an
41 st.d t2, sp, PT_ECFG !! 48 # interrupt setting need_resched
42 csrrd t2, LOONGARCH_CSR_ESTA !! 49 # between sampling and return
43 st.d t2, sp, PT_ESTAT !! 50 LONG_L a2, TI_FLAGS($28) # current->work
44 cfi_st ra, PT_R1 !! 51 andi t0, a2, _TIF_WORK_MASK # (ignoring syscall_trace)
45 cfi_st a0, PT_R4 !! 52 bnez t0, work_pending
46 cfi_st a1, PT_R5 !! 53 j restore_all
47 cfi_st a2, PT_R6 !! 54
48 cfi_st a3, PT_R7 !! 55 #ifdef CONFIG_PREEMPTION
49 cfi_st a4, PT_R8 !! 56 resume_kernel:
50 cfi_st a5, PT_R9 !! 57 local_irq_disable
51 cfi_st a6, PT_R10 !! 58 lw t0, TI_PRE_COUNT($28)
52 cfi_st a7, PT_R11 !! 59 bnez t0, restore_all
53 csrrd ra, LOONGARCH_CSR_ERA !! 60 LONG_L t0, TI_FLAGS($28)
54 st.d ra, sp, PT_ERA !! 61 andi t1, t0, _TIF_NEED_RESCHED
55 cfi_rel_offset ra, PT_ERA !! 62 beqz t1, restore_all
56 !! 63 LONG_L t0, PT_STATUS(sp) # Interrupts off?
57 cfi_st tp, PT_R2 !! 64 andi t0, 1
58 cfi_st u0, PT_R21 !! 65 beqz t0, restore_all
59 cfi_st fp, PT_R22 !! 66 PTR_LA ra, restore_all
>> 67 j preempt_schedule_irq
>> 68 #endif
60 69
>> 70 FEXPORT(ret_from_kernel_thread)
>> 71 jal schedule_tail # a0 = struct task_struct *prev
>> 72 move a0, s1
>> 73 jal s0
>> 74 j syscall_exit
>> 75
>> 76 FEXPORT(ret_from_fork)
>> 77 jal schedule_tail # a0 = struct task_struct *prev
>> 78
>> 79 FEXPORT(syscall_exit)
>> 80 #ifdef CONFIG_DEBUG_RSEQ
>> 81 move a0, sp
>> 82 jal rseq_syscall
>> 83 #endif
>> 84 local_irq_disable # make sure need_resched and
>> 85 # signals dont change between
>> 86 # sampling and return
>> 87 LONG_L a2, TI_FLAGS($28) # current->work
>> 88 li t0, _TIF_ALLWORK_MASK
>> 89 and t0, a2, t0
>> 90 bnez t0, syscall_exit_work
>> 91
>> 92 restore_all: # restore full frame
>> 93 .set noat
>> 94 RESTORE_TEMP
>> 95 RESTORE_AT
>> 96 RESTORE_STATIC
>> 97 restore_partial: # restore partial frame
>> 98 #ifdef CONFIG_TRACE_IRQFLAGS
61 SAVE_STATIC 99 SAVE_STATIC
62 UNWIND_HINT_REGS !! 100 SAVE_AT
63 !! 101 SAVE_TEMP
64 #ifdef CONFIG_KGDB !! 102 LONG_L v0, PT_STATUS(sp)
65 li.w t1, CSR_CRMD_WE !! 103 #if defined(CONFIG_CPU_R3000)
66 csrxchg t1, t1, LOONGARCH_CSR_ !! 104 and v0, ST0_IEP
>> 105 #else
>> 106 and v0, ST0_IE
67 #endif 107 #endif
68 !! 108 beqz v0, 1f
69 move u0, t0 !! 109 jal trace_hardirqs_on
70 li.d tp, ~_THREAD_MASK !! 110 b 2f
71 and tp, tp, sp !! 111 1: jal trace_hardirqs_off
72 !! 112 2:
73 move a0, sp !! 113 RESTORE_TEMP
74 bl do_syscall !! 114 RESTORE_AT
75 <<
76 RESTORE_ALL_AND_RET <<
77 SYM_CODE_END(handle_syscall) <<
78 _ASM_NOKPROBE(handle_syscall) <<
79 <<
80 SYM_CODE_START(ret_from_fork) <<
81 UNWIND_HINT_REGS <<
82 bl schedule_tail <<
83 move a0, sp <<
84 bl syscall_exit_to_user_m <<
85 RESTORE_STATIC 115 RESTORE_STATIC
>> 116 #endif
86 RESTORE_SOME 117 RESTORE_SOME
87 RESTORE_SP_AND_RET 118 RESTORE_SP_AND_RET
88 SYM_CODE_END(ret_from_fork) !! 119 .set at
89 120
90 SYM_CODE_START(ret_from_kernel_thread) !! 121 work_pending:
91 UNWIND_HINT_REGS !! 122 andi t0, a2, _TIF_NEED_RESCHED # a2 is preloaded with TI_FLAGS
92 bl schedule_tail !! 123 beqz t0, work_notifysig
93 move a0, s1 !! 124 work_resched:
94 jirl ra, s0, 0 !! 125 TRACE_IRQS_OFF
95 move a0, sp !! 126 jal schedule
96 bl syscall_exit_to_user_m !! 127
97 RESTORE_STATIC !! 128 local_irq_disable # make sure need_resched and
98 RESTORE_SOME !! 129 # signals dont change between
99 RESTORE_SP_AND_RET !! 130 # sampling and return
100 SYM_CODE_END(ret_from_kernel_thread) !! 131 LONG_L a2, TI_FLAGS($28)
>> 132 andi t0, a2, _TIF_WORK_MASK # is there any work to be done
>> 133 # other than syscall tracing?
>> 134 beqz t0, restore_all
>> 135 andi t0, a2, _TIF_NEED_RESCHED
>> 136 bnez t0, work_resched
>> 137
>> 138 work_notifysig: # deal with pending signals and
>> 139 # notify-resume requests
>> 140 move a0, sp
>> 141 li a1, 0
>> 142 jal do_notify_resume # a2 already loaded
>> 143 j resume_userspace_check
>> 144
>> 145 FEXPORT(syscall_exit_partial)
>> 146 #ifdef CONFIG_DEBUG_RSEQ
>> 147 move a0, sp
>> 148 jal rseq_syscall
>> 149 #endif
>> 150 local_irq_disable # make sure need_resched doesn't
>> 151 # change between and return
>> 152 LONG_L a2, TI_FLAGS($28) # current->work
>> 153 li t0, _TIF_ALLWORK_MASK
>> 154 and t0, a2
>> 155 beqz t0, restore_partial
>> 156 SAVE_STATIC
>> 157 syscall_exit_work:
>> 158 LONG_L t0, PT_STATUS(sp) # returning to kernel mode?
>> 159 andi t0, t0, KU_USER
>> 160 beqz t0, resume_kernel
>> 161 li t0, _TIF_WORK_SYSCALL_EXIT
>> 162 and t0, a2 # a2 is preloaded with TI_FLAGS
>> 163 beqz t0, work_pending # trace bit set?
>> 164 local_irq_enable # could let syscall_trace_leave()
>> 165 # call schedule() instead
>> 166 TRACE_IRQS_ON
>> 167 move a0, sp
>> 168 jal syscall_trace_leave
>> 169 b resume_userspace
>> 170
>> 171 #if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR5) || \
>> 172 defined(CONFIG_CPU_MIPSR6) || defined(CONFIG_MIPS_MT)
>> 173
>> 174 /*
>> 175 * MIPS32R2 Instruction Hazard Barrier - must be called
>> 176 *
>> 177 * For C code use the inline version named instruction_hazard().
>> 178 */
>> 179 LEAF(mips_ihb)
>> 180 .set MIPS_ISA_LEVEL_RAW
>> 181 jr.hb ra
>> 182 nop
>> 183 END(mips_ihb)
>> 184
>> 185 #endif /* CONFIG_CPU_MIPSR2 - CONFIG_CPU_MIPSR6 or CONFIG_MIPS_MT */
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